贝氏隐孢子虫在鸡体内发育的形态学特征及其对寄生器官的影响

Morphologic Feature of Cryptosporidium baileyi Endogenous Developmental Stages in Chickens and Influence on Parasitic Organs of Host

取 2日龄海兰雏鸡 5 0只 ,分为 5组 ,分别接种 0、 0 8× 10 6、 1 6× 10 6、 3 2× 10 6、 6 4× 10 6个鸭源贝氏隐孢子虫 (Cryptosporidiumbaileyi)卵囊。接种后在不同的时间间隔内剖杀雏鸡 ,取法氏囊、气管和喉头。扫描电镜观察发现贝氏隐孢子虫主要寄生在鸡的喉头、法氏囊、气管。裂殖体有 2种类型 :Ⅰ型裂殖体含 8个裂殖子 ,Ⅱ型裂殖体含 4个裂殖子。子孢子或裂殖子在钻入过程中 ,虫体逐渐由香蕉形过渡到鼓槌形 ,最后形成球形的滋养体。带虫空泡分为有球形残体的带虫空泡和无球形残体的带虫空泡。观察到小配子的释放和虫体寄生于杯状细胞的现象。贝氏隐孢子虫寄生于气管引起纤毛倒伏、排列紊乱、纤毛融合、脱落 ;致使法氏囊上皮肿胀 ,法氏囊粘膜表面形成皱褶 ,微绒毛脱落、融合、排列紊乱 ,粘液性分泌物增多 。

Fifty Hy Line chicks were divided into 5 groups 10 for each. They were orally inoculated with 0,0 8×10 6,1 6×10 6,3 2×10 6,6 4×10 6 oocysts of Cryptosporidium baileyi respecitivelly when they were 2 days old.The chicks were killed at different intermission time postinfection,and their trachea,burea of Fabricious(BF) and throat were taken for study by scanning electron microscopy. C baileyi endogenous development occurred primarily in the trachea,BF and throat.There are two kind of schizont (type Ⅰ meronts contained eight merozoites,and types Ⅱ meronts contained four merozoites).The freed sporozoites or merozoites attached to epithelial cells where they became drumstick like from banana like,and then formed spherical trophozoites.There were two kinds of parasitophorous vacuoles (one had spherical residual body in and the other had no such thing).Microgamete escaping from maternal body and endogenous development stages in goblet cell were observed.Cryptosporidia caused the cilia of chicken trachea lodging, disordering,desquamating and fusing,and the epithelium membrane of bursa swollening with microvillus desquamation,fusion,and disorder,increasing mucus secretory product,and infiltrating mononuclear cell.Rugae were formed on the epithelium membrane because of epithelial cell hypertrophy or hyperlasia.